"We don't normally talk about testing, but it tested so well in all four quadrants [male and female, over and under 25 years old]," said the network exec.

"Of course, it's Joss Whedon - he made Buffy the Vampire Slayer so he knows how to create not just great television, but great television with great relationships at the heart of it.

"Not only does it have great relationships and humor, but also it has the promise of the Marvel franchise and that brings it a sense of wonder and excitement and adventure. We think it's driven by character and we think it's going to bring a wider audience to us."

Marvel's Agents of S.H.I.E.L.D. - which stars Clark Gregg as Agent Phil Coulson - will air on Tuesdays nights at 8/7c in the fall, the same slot occupied by popular drama NCIS on CBS, but Lee insisted that he is not concerned about the clash.

"First of all, every single hour on the schedule is up against competition, but we believe that S.H.I.E.L.D. is particularly good at 8/7c, because... it's going to recruit a whole new audience," he said.

"We think it has a built-in audience 'cos it's associated with the amazing Avengers franchise, and we don't necessarily think that audience is the same as NCIS [viewers] so we have high hopes for it."